Image Format Converter

In my day-to-day website operations, I often encounter situations where I need to convert files such as PNGs and JPGs to the WebP format to speed up page loading times.

Converting them one by one is very tedious, so I developed a simple tool that makes it easy toBatch ConversionVarious common image formats, including PNG, JPG, WebP, and GIF, while preserving the original folder structure.

For those who need to useOnline Tool to Convert PNG to WebPOr it may be necessary to process a large number ofConvert JPG to WebPIt’s a great choice for anyone who needs to process images. It can also serve as a local solution for batch converting image formats online—simply double-click to get started. Since it operates locally, it ensures the privacy and security of your images, while offering the same user experience as cloud-based tools.

👉 Project Address:https://github.com/cheng01315/Image-Format-Converter

1. Features and Functions

• 📦 Multi-format support – JPG/JPEG, PNG, GIF, WebP, BMP, TIFF, and other formats can all be converted to and from one another
• ⚡ Batch Conversion – Perform all operations on all images in a folder at once—quick and convenient,Batch Conversion of Image Formats Online (Runs Locally)。
• 📁 Preserve the directory structure – The output folder is the same as the source folder and can be used forWebP Image Conversion Scenarios for Independent Websites。
• 🪟 Cross-platform, no installation required – Run directly on Windows Start.exe, requires no Python, and is aPortable Image Converter (No Installation Required)
• 💬 User-Friendly Command Line – Simple interactive prompts with formatting instructions—geek-friendly

2. Supported Formats

3. Instructions for Use

3.1 Windows (No Python Required)

1. 从 Press Releases Download Page Start.exe
2. 在 Start.exe Create in the same directory input 和 output Folder
3. Place the images you want to convert into input Folder
4. Double-click Start.exe Run
5. Select the desired target format based on what is displayed on the screen (for example, Convert PNG to WebP 或 Convert JPG to WebP）

3.2 Running from Source Code (Cross-Platform)

# Installation Dependencies
pip install Pillow

# Running the Program
python Start.py

4. Project Structure

image-format-converter/
├── Start.exe # Windows executable file (~14MB)
├── Start.py # Python source code
├── input/ # Place images to be converted here
└── output/ # Output location for converted images

5. How It Works (Easy to Understand)

1. Scan input All supported image formats in the folder
2. List the detected formats and their corresponding descriptions
3. Prompt the user to enter the target format (e.g., WebP, PNG)
4. Batch convert while preserving the directory structure as-is to output

6. Requirements

• Python 3.x (required only when running source code)
• The Pillow library (pip install Pillow）
• Windows System (Precompiled Executable)

7. A Quick Tip

• 🖼️ Optimizing Website Images: Batch convert PNG/JPG files to WebP; this typically reduces the file size to 30%–50% of the original image size, and can be done directly.Improving Web Page Load Speed, toGoogle SEO Image Format OptimizationVery helpful. Google explicitly recommends using WebP, and batch converting images with this tool will significantly improve your PageSpeed Insights score.
• 📂 Supports nested subfolders, so you don't have to worry about disrupting the original structure—it's perfect forBatch Conversion of WebP Images for Independent WebsitesWorkflow.
• ⚙️ If you want to convert to the AVIF format (a new-generation, more efficient format), this feature isn't built into the current version, but you can file an issue, and I'll add support for it in a future update.Online AVIF Format Converter(This is still a local conversion, with an experience similar to that of an online tool.)
• 💡 If this is your first time using this feature, we recommend copying a few images to test it first and confirming the results before processing them in batches.